text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  // This is a small utility that watches for and logs network changes.
  // It prints out the current network connection type and proxy configuration
  // upon startup and then prints out changes as they happen.
  // It's useful for testing NetworkChangeNotifier and ProxyConfigService.
  // The only command line option supported is --ignore-netif which is followed
  // by a comma seperated list of network interfaces to ignore when computing
  // connection type; this option is only supported on linux.
  
  #include <memory>
  #include <string>
  #include <unordered_set>
  
  #include "base/at_exit.h"
  #include "base/command_line.h"
  #include "base/compiler_specific.h"
  #include "base/json/json_writer.h"
  #include "base/logging.h"
  #include "base/macros.h"
  #include "base/message_loop/message_loop.h"
  #include "base/run_loop.h"
  #include "base/strings/string_split.h"
  #include "base/values.h"
  #include "build/build_config.h"
  #include "net/base/network_change_notifier.h"
  #include "net/proxy_resolution/proxy_config.h"
  #include "net/proxy_resolution/proxy_config_service.h"
  #include "net/proxy_resolution/proxy_resolution_service.h"
  
  #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
  #include "net/base/network_change_notifier_linux.h"
  #endif
  
  #if defined(OS_MACOSX)
  #include "base/mac/scoped_nsautorelease_pool.h"
  #endif
  
  namespace {
  
  #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
  // Flag to specifies which network interfaces to ignore. Interfaces should
  // follow as a comma seperated list.
  const char kIgnoreNetifFlag[] = "ignore-netif";
  #endif
  
  // Conversions from various network-related types to string.
  
  const char* ConnectionTypeToString(
      net::NetworkChangeNotifier::ConnectionType type) {
    switch (type) {
      case net::NetworkChangeNotifier::CONNECTION_UNKNOWN:
        return "CONNECTION_UNKNOWN";
      case net::NetworkChangeNotifier::CONNECTION_ETHERNET:
        return "CONNECTION_ETHERNET";
      case net::NetworkChangeNotifier::CONNECTION_WIFI:
        return "CONNECTION_WIFI";
      case net::NetworkChangeNotifier::CONNECTION_2G:
        return "CONNECTION_2G";
      case net::NetworkChangeNotifier::CONNECTION_3G:
        return "CONNECTION_3G";
      case net::NetworkChangeNotifier::CONNECTION_4G:
        return "CONNECTION_4G";
      case net::NetworkChangeNotifier::CONNECTION_NONE:
        return "CONNECTION_NONE";
      case net::NetworkChangeNotifier::CONNECTION_BLUETOOTH:
        return "CONNECTION_BLUETOOTH";
      default:
        return "CONNECTION_UNEXPECTED";
    }
  }
  
  std::string ProxyConfigToString(const net::ProxyConfig& config) {
    std::unique_ptr<base::Value> config_value(config.ToValue());
    std::string str;
    base::JSONWriter::Write(*config_value, &str);
    return str;
  }
  
  const char* ConfigAvailabilityToString(
      net::ProxyConfigService::ConfigAvailability availability) {
    switch (availability) {
      case net::ProxyConfigService::CONFIG_PENDING:
        return "CONFIG_PENDING";
      case net::ProxyConfigService::CONFIG_VALID:
        return "CONFIG_VALID";
      case net::ProxyConfigService::CONFIG_UNSET:
        return "CONFIG_UNSET";
      default:
        return "CONFIG_UNEXPECTED";
    }
  }
  
  // The main observer class that logs network events.
  class NetWatcher :
        public net::NetworkChangeNotifier::IPAddressObserver,
        public net::NetworkChangeNotifier::ConnectionTypeObserver,
        public net::NetworkChangeNotifier::DNSObserver,
        public net::NetworkChangeNotifier::NetworkChangeObserver,
        public net::ProxyConfigService::Observer {
   public:
    NetWatcher() = default;
  
    ~NetWatcher() override = default;
  
    // net::NetworkChangeNotifier::IPAddressObserver implementation.
    void OnIPAddressChanged() override { LOG(INFO) << "OnIPAddressChanged()"; }
  
    // net::NetworkChangeNotifier::ConnectionTypeObserver implementation.
    void OnConnectionTypeChanged(
        net::NetworkChangeNotifier::ConnectionType type) override {
      LOG(INFO) << "OnConnectionTypeChanged("
                << ConnectionTypeToString(type) << ")";
    }
  
    // net::NetworkChangeNotifier::DNSObserver implementation.
    void OnDNSChanged() override { LOG(INFO) << "OnDNSChanged()"; }
    void OnInitialDNSConfigRead() override {
      LOG(INFO) << "OnInitialDNSConfigRead()";
    }
  
    // net::NetworkChangeNotifier::NetworkChangeObserver implementation.
    void OnNetworkChanged(
        net::NetworkChangeNotifier::ConnectionType type) override {
      LOG(INFO) << "OnNetworkChanged("
                << ConnectionTypeToString(type) << ")";
    }
  
    // net::ProxyConfigService::Observer implementation.
    void OnProxyConfigChanged(
        const net::ProxyConfigWithAnnotation& config,
        net::ProxyConfigService::ConfigAvailability availability) override {
      LOG(INFO) << "OnProxyConfigChanged(" << ProxyConfigToString(config.value())
                << ", " << ConfigAvailabilityToString(availability) << ")";
    }
  
   private:
    DISALLOW_COPY_AND_ASSIGN(NetWatcher);
  };
  
  }  // namespace
  
  int main(int argc, char* argv[]) {
  #if defined(OS_MACOSX)
    base::mac::ScopedNSAutoreleasePool pool;
  #endif
    base::AtExitManager exit_manager;
    base::CommandLine::Init(argc, argv);
    logging::LoggingSettings settings;
    settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
    logging::InitLogging(settings);
  
    // Just make the main message loop the network loop.
    base::MessageLoopForIO network_loop;
  
    NetWatcher net_watcher;
  
  #if defined(OS_LINUX) && !defined(OS_CHROMEOS)
    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
    std::string ignored_netifs_str =
        command_line->GetSwitchValueASCII(kIgnoreNetifFlag);
    std::unordered_set<std::string> ignored_interfaces;
    if (!ignored_netifs_str.empty()) {
      for (const std::string& ignored_netif :
           base::SplitString(ignored_netifs_str, ",", base::TRIM_WHITESPACE,
                             base::SPLIT_WANT_ALL)) {
        LOG(INFO) << "Ignoring: " << ignored_netif;
        ignored_interfaces.insert(ignored_netif);
      }
    }
    std::unique_ptr<net::NetworkChangeNotifier> network_change_notifier(
        new net::NetworkChangeNotifierLinux(ignored_interfaces));
  #else
    std::unique_ptr<net::NetworkChangeNotifier> network_change_notifier(
        net::NetworkChangeNotifier::Create());
  #endif
  
    // Use the network loop as the file loop also.
    std::unique_ptr<net::ProxyConfigService> proxy_config_service(
        net::ProxyResolutionService::CreateSystemProxyConfigService(
            network_loop.task_runner()));
  
    // Uses |network_change_notifier|.
    net::NetworkChangeNotifier::AddIPAddressObserver(&net_watcher);
    net::NetworkChangeNotifier::AddConnectionTypeObserver(&net_watcher);
    net::NetworkChangeNotifier::AddDNSObserver(&net_watcher);
    net::NetworkChangeNotifier::AddNetworkChangeObserver(&net_watcher);
  
    proxy_config_service->AddObserver(&net_watcher);
  
    LOG(INFO) << "Initial connection type: "
              << ConnectionTypeToString(
                     net::NetworkChangeNotifier::GetConnectionType());
  
    {
      net::ProxyConfigWithAnnotation config;
      const net::ProxyConfigService::ConfigAvailability availability =
          proxy_config_service->GetLatestProxyConfig(&config);
      LOG(INFO) << "Initial proxy config: " << ProxyConfigToString(config.value())
                << ", " << ConfigAvailabilityToString(availability);
    }
  
    LOG(INFO) << "Watching for network events...";
  
    // Start watching for events.
    base::RunLoop().Run();
  
    proxy_config_service->RemoveObserver(&net_watcher);
  
    // Uses |network_change_notifier|.
    net::NetworkChangeNotifier::RemoveDNSObserver(&net_watcher);
    net::NetworkChangeNotifier::RemoveConnectionTypeObserver(&net_watcher);
    net::NetworkChangeNotifier::RemoveIPAddressObserver(&net_watcher);
    net::NetworkChangeNotifier::RemoveNetworkChangeObserver(&net_watcher);
  
    return 0;
  }
  